SQL Aliases
Here is a clear, practical guide to SQL Aliases, how they work, and when you should use them. Aliases make queries shorter, cleaner, and easier to read.
What Are SQL Aliases?
SQL aliases create a temporary name for a column or table within a query.
They do not change actual table or column names.
They exist only during query execution.
You create an alias using the AS keyword (optional in most engines).
Column Alias Syntax
AS is optional:
Column Alias Examples
1. Rename a column in result
2. Create readable calculated columns
3. Format date/time fields
Table Alias Syntax
(Again, AS is optional.)
Table Alias Examples
1. Shorten long table names
2. Self-join example
Aliases in Aggregations
Aliases make grouped results readable:
Aliases in Subqueries
Aliases are required for subqueries used as tables:
Best Practices
- Use short aliases to improve readability
- Always alias calculated columns
- Always alias subqueries
- Use meaningful aliases (
u,p,ofor users, products, orders) - Avoid single-letter aliases in complex queries
